Pressure-operated valve-gear-shifting mechanism.



S. H. LEWiS. PRESSURE OPERATES VALVE GEAR SHIFTING MECHANISM.

APPLlmm-m' FILED me. 1911. v

Patented Jan. 8,1918.

SAMUEL H. LEWIS, OF RICEMGND, VIQG'INIA.

PRESSURE-GYEBATED VALVE-GEAR-SHIFTING Application filed January 6, 1917.

To all whom it may COHGBW/L.

Bt it known that I, SAMUEL H. Lawns, a citizen of the United States. residingat Richmond, in the county of Henrico and State of Virginia, have invented certain new and useful Improvements in Pressure-Operated Valve-Gear-Shifting Mechanism, of which the following is a specification.

My invention relates to improvements in fiuid pressure operated apparatus for operating or shifting the valve gear of steam engines, particularly railway locomotives, While ,not'necessarily restricted to this use, of the general type shown and described in Letters Patent No. 1,183,213, granted to me under date of March 16, 1916.

An important object of the invention is to provide means whereby the control lever of the apparatus bears a substantially fixed relation with respect to the position or" the locomotive valve gear, at all times, regardless of the degree of fluid pressure, with which the reverse gear is'operated.

A further object of the invention is to provide means of the above mentioned character, adapted to lock the control lever against extensive movement, when the fiuid pressure is insuiiicient to operate the apparatus for shifting the valve gear, or when the shifting piston is stationary.

Other objects and advantages of the in vention will be apparent during the course of the following description In the accompanying drawings forming a part of this specification and in which like numerals are employed to designate like parts throughout the same,

Figure 1 is a side elevation of apparatus embodying the invention,

Fig. 2 is a side elevation of a valve casing, parts being removed,

Fig. 3 is acentral vertical sectional View through the valve structure or mechanism,

Fig. 4 is a horizontal sectional View taken on line 4-4: of Fig. 2,

Fig. 5 is a side elevation of the control valve, and,

Fig. 6 is a detail section through a neutral late In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral 10 designates a preferably horizontally arranged cylinder, which is secured to the locomotive at any suitable point. Mounted to reciprocate within this cylinder is a piston 11, rigidly Specification of Letters Patent.

MECHANISM.

Patented Jan. a, 1932.

Serial no. 140,922.

secured to a piston rod 12, operating through stufing boxes 13. Pivotally connected with the iorward end or the piston rod 12, as shown at 14, is a pitman or link 15, having suitable connection with the valve gear of the locomotive, to shift it.

Rigidly connected with the forward end of the piston rod 12 is a depending crank 16, having its lower end pivotally connected with a link 17, pivotally connected with the lower end of a preferably vertically swinging lever 18. The lever 18 is pivotally connected between its ends, as shown at 19, with an arm or bracket 20, rigidly secured to the cylinder 10.

Piv0tally connected with the upper end of the lever 18 is a reach rod 21, as shown at 22.

The numeral. 23 designates a valve structure or mechanism as a whole, comprising a casing or casting 24, having a fiat face 25, and provided with an inlet port 26, communicating with a pipe 27, which leads to a source of pressure, such as a compressed air storage tank, not shown. ihe inlet port 26 communicates with an inlet port 28, discharging into a chamber 29, to be hereinafter referred to. lhe inlet port 28 passes through the annular flange 30, formed upon the casting 24, as shown. Arranged upon opposite sides of the inlet port are ports 31 and 32, which lead into pipes 33 and 34:, discharging into the opposite ends of the cylinder 10. lhe ports 31 and 32 have their upper ends discharging into segmental grooves 35 and 36, arranged upon opposite sides of the inlet port, as shown. The numeral 3? designates an exhaust port, extending through the face 25 of the casting and disposed between the grooves 35 and 36..

Disposed to rotate or turn within the flange 80 in slidable contact with the face 25, is a valve 38, having its inner side provided with a surface groove or port 39, the inner end of which is in permanent registration with the exhaust port 8?, while its outer end is adapted to be alternately moved into registration with the grooves 35 and 38. The valve 38 is provided in its ,lower portion with a transverse port or opening 40. lhis transverse opening it; is arranged between the segmental grooves 35 and 36, and when the valve 38 is in the normal position the opening 40 preferably has its ends arranged in line to line relation with the grooves 35 and 36, whereby a leakage of pressure is permitted into the grooves 35 and 36, such pressure passing to the opposite ends of the cylinder 10, to normally retain the pressure equal upon opposite sides of the piston. The chamber 29 is disposed between the valve 38 and a head 41, which closes the chamber. The pressure from the port 26 thus circulates upon the top of the valve 38, which serves to retain it securely seated.

The valve 38 is provided with a post 42, for turning it. which is rectangular in crossscction and adapted to fit within an opening 43, formed in the head 44 of a stud 45. The head 44 is adapted to contact with a washer 46, and a compressible coil spring 47 is arranged between the post 42 and the end wall of an opening 48 formed in the stud 45, thus serving to hold the valve 38 upon its seat and the head 44 in contact with the ring or washer 46, for preventing leakage.

The head 41 is provided with a flange 49, forming with a ring or collar 50, an annular groove 51, for receiving a suspension'collar or strap 52. this suspension collar or strap is provided at its lower end with a depend ing apertured knuckle 53, carrying a pivot element 54. The reach rod 21 has its rear end apertured for receiving the pin 54, whereby it is pivotally connected with the knuckle The pin 54 extends outwardly into a longitudinal opening or slot 55, formed in the lower end of a vertically swinging combination lever 56. This combination lever extends upwardly for pivotal connection with a controlling lever 57, by means of a pin 58 or the like. The controlling lever carries the ring 50, which is preferably formed integral therewith and pivotally mounted upon the flange 30. Rigidly connected with the upper portion of the combination lever 56, by means of bolts 58 or the like, is a toothed segment or gear 59, engaging the pinion 47, for turning it. he pinion 47' is rigidly secured to the stud 45. The control lever 57 operates in proximity to a stationary toothed quadrant 60, rigidly secured to the upper ends of arms 61, formed integral with the casting 24. The lever 57 is provided with latch means 62 to cooperate with the quadrant and lock the lever in the desired adjusted position. The lever 57 is provided with a recess 57, for receiving a spring pressed ball latch 58, ax] apted to enter a notch 59 formed upon the. lower edge of the quadrant 60, and

equidistantly spaced from its ends. The function of this construction is to provide a neutral latch or means whereby the operator may quickly and conveniently ascertain when the control lever 57 is in the neutral position.

direction, when there is not sufficient fluid pressure within the cylinder 10, for shifting the piston 11. While it is believed that this result may be accomplished in various ways, I will now pr ceed to describe an example of a specific construction for accomplishing the result, it being understood however that other means may be employed.

This means comprises a. stop-member or dowel 63, the inner end of which is rigidly mounted within an opening or recess 64 formed in the casting 24. The StOIJ'mQDIbOI 63 is arranged within the exhaust groove 39, and is sufliciently short so that it does not impede the free passage of. pressure thereabout. As clearly shown in Fig. 5, the width or diameter of the stop-member 63 is less than the body of the groove 39, whereby the valve. 38 may be turned a slight distance in either direction, and sufficiently for bringing the groove 39 into communication with the upper end of one of the grooves 35 and 36 and the opening 40 into communication with the lower end of the other segmental groove. It is obvious however, that the valve 38 can only be turned in either direction for a distance corresponding to the space between the stop-member and the wall of the groove 39, whereby it is impossible to move the control lever 57 for a considerable distance prior to the movement of the piston.

The operation of the apparatus is as follows:

When the control lever 57 is in the neutral position the valve 38 is in the neutral or normal position, whereby the ends of the admission port 40 are arranged in substantially line to line relation with the lower ends of the grooves 35 and 36. There is then a passage or leakage of fluid pressure from the opening or port 40 into the grooves and 36, which is conducted through the pipes 33 and 34 to the opposite ends of the cylinder 10, upon opposite sides of the piston 11, thus equalizing pressure upon the opposite sides, and tending to hold the piston against movement. lVhen it is desired to shift the valve gear to drive the locomotive forwardly the control lever 57 is moved forwardly. The control lever 57 cannot be shifted but for a limited distance, for instance ior one or two teeth or notches of. the quadrant, as the turning movement of the valve 38 is restricted by the stop-member 63. The lever 57 may be assumed to be held in the shifted position by the operator and the combination lever 56 will then turn upon the pin 58 as a pivot, and when its lower end is swung rearwardly, the segmental gear 59 is swung rearwardly, whereby it turns the pinion 47' counter-clockwise for returning the valve 38 to the neutral position. It is thus apparent that the combination lever and associated elements tend to return the valve-3S to the neutral position as soon as the piston 11 begins to move. and by the operator holding the latch means of the control lever 57 inactive he may advance the control lever inproportion to the extent of movement of the piston 11. but cannot move the control lever for a considerable distance when the piston does not move, as upon the absence of suflicient fiuid pressure within the cylinder to shift the piston. Vhen the control lever is shifted to the right. as above stated, the upper end of the combination lever 56 is swung forwardly, carrying with it the segmental gear 59. whereby the pinion 4:7 is turned clockwise. This clockwise movement of the pinion 47 turns the valve 38 clockwise, whereby the port 40 is moved into registration with the segmental groove 35 and out of registration with the segmental groove 36, the exhaust port 39 being simultaneously moved into registration with the groove 36. It is thus apparent that pressure will pass through the port '26. port 28, chamber 29. opening 40, port 31. pipe 32). into the left end of the cylinder and will exhaust from the opposite end of the cylinder through the pipe 34, port 32. groove 36, port and through port 37 to the atmosphere. The pressure upon the rear or left side of the piston 11 moves it forwardly. This movement of the piston is transmitted to the rod or pitman which shifts the valve gear. Upon the forward movement of the piston rod 12. the crank 16 is moved forwardly, swinging the lower end of the lever 18 forwardly and its upper end rearwardly. The rearward movement of the upper end of the lever 18 is transmitted to the reach rod 21 and by it to the combination lever 56.

WVhen the control lever is swung rearr The locking of the lever prevents independent movement of the same, with respect to the valve gear. which is the cause of numerous accidents. since the position of the lever would not then indicate the true position of the valve gear.

It is to be understood that the form of my invention. herewith shown and described is to be taken as a preferred example of the same, and that various changes in the shape, size, and arrangements of parts may be resorted to without departing from the spirit of the invention or the scope of the subjoined claim.

Having thus described the invention, I claim In apparatus of the character described, the combination with a cylinder, of a piston mounted to reciprocate therein, means for connecting the piston with the valve gear of a steam engine, valve mechanism for controlling the inlet and exhaust of fluid pressure to and from the opposite ends of the cylinder including a movable valve, a manually operated lever connected with the valve to move the same to the open position. automatically operating means connected with the valve and the piston to move the valve to the closed position upon the movement of the piston, and a stationary stop element separate from the automatically operating means and contacting with the valve for restricting its movement without restricting the movement of the fmanually'operatetl lever when the automatically operating means is active and restricting the movement of the manually operated lever when the auto-' matically operating means is inactive.

In testimony whereof I atiix my signature in presence of two witnesses.

' SAMUEL H. LEWIS. Witnesses:

James L. CRAWFORD,

G. C. Janvrs. 

